Lord Foster sells stake to 3i

Lord Foster, the architect behind Swiss Re's famous Gherkin building and the new Wembley Stadium, has sold a stake in the practice he founded 40 years ago to its first external investors.

Private equity group 3i has bought a minority holding in Foster & Partners and is set to help fund the group's plans to grow internationally.

Lord Foster will remain as chairman, retaining a 'significant' shareholding, and the group has expanded the equity ownership of the firm to see all 14 senior directors now own a stake in the practice.

Foster & Partners has not disclosed the size of the holding sold to 3i, or how much the deal was worth, but it is thought that the architectural firm is worth around £300m in total.

3i has bought a stake both in the company and in the 'Foster' brand. Lord Foster will continue to be the single largest shareholder, although it is understood he previously held a much larger 90% stake in the group.

The 71-year-old is one of the wealthiest people in Britain after building the firm up into an international success with 1,000 staff worldwide. He made it into the Sunday Times Rich List for the first time this year, ranked 249th place with a £245m personal fortune.

The firm has 18 offices globally and has been involved in some of the world's highest profile architectural designs, such as HSBC's headquarters in Hong Kong and the world's tallest road bridge, the Millau Viaduct in France.

The company said the stake sale would help it expand to new markets, in particular large-scale global infrastructure projects, with the help of 'complementary global footprints' between 3i and Foster & Partners.

It is believed that Lord Foster wants to embark on an aggressive expansive plan, with aims to build the firm's international office network to around 30.

He said: 'As Foster & Partners enters its 40th year, I was keen to ensure the long-term future of the practice. By creating a new management and shareholder infrastructure, we can now grow and develop in the ways that we want, whilst staying true to our values.'

Foster & Partners has also created an executive management team, with partner Mouzhan Majidi appointed as chief executive.